The present invention relates generally to a temperature responsive signaling device, and more particularly, to such a device for use at locations where diesel powered trucks congregate.
Cold weather presents a problem for diesel powered automotive vehicles, especially trucks of the tractor-trailer variety. In cold weather, diesel engines can encounter problems in starting, even if 15W40 motor oil is used. A large diesel engine acts as a 2500 pound plus heat sink, which at cold temperatures can prevent sufficient pressure from building up within the diesel engine to allow the engine to start. As a result, truckers often leave their vehicles running in cold weather in an attempt to overcome the problem.
However, diesel engines consume 3-5 gallons per hour when idling. Additionally, there are other disadvantages associated with idling besides increased fuel consumption, including increased air pollution, increased engine wear, and an increase in the contamination of run-off water from the concrete or blacktop area where the vehicles are parked. One large diesel carrier conducted a study which determined that it wasted over 1.8 million gallons of fuel one year due to unnecessary idling. This figure translated to over 1.4 million dollars in increased fuel costs, all due to unnecessary idling.
Although the simple solution would seem to be the discontinuation of the practice of idling engines, there are two major drawbacks to that plan. The first problem is that despite the apparent high cost of wasted fuel, that cost is minor compared to the maintenance costs which would be encountered if all diesel engines were shut down in too cold of weather. A second, yet related problem to the first, is that truck drivers are supposed to spend only ten hours of driving time per day, with the "driving time" commencing once the driver leaves his terminal or truck stop and returns to his vehicle. In cases where the truck refuses to start, the driver still is having that time count against him, such that if his rig can be fixed, he will be prone to speed or even perhaps drive in a reckless manner in an attempt to make up for lost time.
One solution to the problem of cold weather starts has been block heaters, which serve to heat the oil of a parked truck. However, a block heater can only be used on one vehicle at a time and places where trucks congregate in large numbers, such as terminals, truck stops, or freeway rest areas, at best provide only a limited number of such heater units.
The traditional approach to the problem has been to permit the trucks to idle when the temperature is sufficiently high enough to hopefully preclude problems with starting. On the other hand, truck drivers are encouraged to leave their vehicles idling when temperatures become sufficiently cold enough that the likelihood of starting problems becomes a real concern. In practice, individuals often rely on their best estimate as to how cold it is, in deciding whether to permit their trucks to idle. Occasionally, truck stops or terminals employ individuals to keep track of the temperature, and if it reaches a certain level, then they manually go from truck to truck to start their engines, or insert the heater units into the truck's oil. Sometimes, terminals have had a single light, which drivers could interpret as being a signal to either idle or not idle their vehicles. However, the specifics of operation for these light systems is unclear.
It is thus apparent that the need exists for an idle/no idle light system for use at locations where diesel powered trucks congregate, to reduce fuel costs as well as minimize maintenance costs associated with excessive idling in cold weather.